The Effect Of Exhaustive Intervention On Cardiovascular And Cerebrovascular Health In CAMR_TG Transgenic Mice

According to the World Health Organization,approximately 17,000,000 people die of cardiovascular and cerebrovascular diseases per year.Based on their peculiarity with high morbidity,mortality and disability as well as multi-complications,cardiovascular and cerebrovascular diseases pose a threat to human health.Cardiovascular and cerebrovascular diseases are associated with calcium-associated proteins such as Cacium channel RyR and its regulators including CAMRs,PP2A,and FNs,N-cadherin,PTEN,etc.These proteins can activate or inhibit the CICR pathway through the regulation of RyR configuration,which result in the regulation of muscle contraction.When the pathway is disturbed,the muscle present disorders of excitation-contraction coupling,which can cause abnormal vascular tone and block the myocardial cell signal transduction,resulting in arrhythmia,hypertension and intracerebral hemorrhageMany researches have shown that moderate physical activity is beneficial for the remission of cardiovascular and cerebrovascular diseases,especially for the recovery of intracerebral hemorrhage.However,excessive physical activity may disturb the regulation of calcium-associated proteins,which trigger the sudden cardiac or cerebral death.Therefore,the selection and control of physical activity mode and intensity are very important especially for the patients with cardiovascular and cerebrovascular diseases or those with similar traits.In this study,the CAMR_TG and the same genetic background wild type mice were used as experimental and control mice respectively.There was a 3-weeks treadmill physical and one-off exhaustive physical activity.The experimental mice were grouped into four:wild type sedentary mice(WT-S),wild type exhaustive physical interference mice(WT-Ex),transgenic sedentary mice(TG-S)and transgenic exhaustive physical interference mice(TG-Ex).The objective of the study is to observe the influence of exhaustive physical activity on cardiac,cerebral and vascular function.Physiological monitoring indictors were electrocardiogram,blood pressure,magnetic resonance imaging,vessel contraction,etc.Pathological changes of heart,brains and vessels were observed through histological analysis using H&E,Trichrome,Congo Red,Perls'Prussian Blue,Turnbull Blue and Orcein stainings.Immumohistochemical reactions were performed to detect the locations of CAMR1 and CAMR2 expression.Western Blot was also performed to examine the quantity of CAMRs,N-cadherin,PP2A,FNs,and PTEN in mice tissues under different conditions.The results are as followings:(1)Physiological monitoring indictors:Arrhythmia occurred in transgenic mice and the symptom aggravated after exhaustive physical activity,which triggered sudden cardiac death.Subarachnoid hemorrhage which triggered sudden cerebral death was observed in transgenic mice,and the MRI results confirmed the above symptom.The results of vessel contraction measurement show that,compared with wild type mice,the mesenteric arteries of transgenic mice were slightly more sensitive to contraction stimulation with no statistic significant differences,but they were extremely significantly less sensitive to relaxation stimulation(TG-S compared with wild type P<0.001,TG-Ex compared with wild type P<0.01),which implied the higher vascular tone of transgenic mice.(2)Histopathology abnormality:Myocardial fibrosis was observed in TG-S,TG-Ex and WT-Ex mice but not WT-S mice hearts.Hemorrhagic lesions which were located in subarachnoid space,cerebral cortex and cerebellum were observed in TG-Ex mice brain.There were amyloid plaques on the vascular wall where the hemorrhagic-lesions were located,corresponding with MRI results.However,the iron accumulation were not observed in the tissues.The arterial laminas of transgenic mice were discontinuous with multi-breakages and a non-uniform aorta thickness.(3)Immunohistochemistry staining analysis:In mouse hearts,CAMR1 were mainly detected at septum,epicardium of left and right ventricular wall as will as myocardium and endocardium of left ventricular wall;whereas in mice brains,it was mainly detected at cerebral cortex,thalamus and cerebellum.In mice hearts,CAMR2 were mainly detected at epicardium,myocardium and endocardium of ventricular walls as well as ventricular septum;while it was mainly detected at cerebral cortex and caudate putamen of the brains.(4)Western Blot analysis:In mice hearts,compared with wild type mice,the expression of CAMR 1 and CAMR2 in transgenic mice slightly decreased with no statistic significant differences,however,in TG-Ex mice they slightly increased with no statistic significant differences;compared with wild type mice,the expression of N-cadherin was up-regulated in transgenic mice(WT-S compared with TG-S,P<0.05;WT-Ex compared with TG-Ex,P<0.01)and it was up-regulated in TG-Ex mice compared with TG-S mice(P<0.05);compared with WT-S mice,the expression of PP2A C in TG-S mice was down-regulated(P<0.001)but it was up-regulated in TG-Ex mice compared with WT-Ex and TG-S mice(P<0.001).In mice brains,compared with wild type mice,the expression of CAMR1 and CAMR2 was up-regulated in transgenic mice(WT-S compared with TG-S,CAMR1 P<0.001,CAMR2 P<0.01;WT-Ex compared with TG-Ex,CAMR1 P<0.05,CAMR2 P<0.01),meanwhile compared with TG-S mice,the expression of CAMR1 in TG-Ex mice slightly decreased with no statistic significant differences,it of CAMR2 was up-regulated(P<0.05);compared with wild type mice,the expression of N-cadherin was down-regulated(WT-S compared with TG-S,P<0.05;WT-Ex compared with TG-Ex,P<0.01),meanwhile compared with TG-S mice,it slightly decreased with no statistic significant differences.Compared with wild type mice,the expression of PP2A C,FN-1 and PTEN were decreased with no statistic significant differences;compared with TG-S mice,the expression of FN-1 and PTEN decreased with no statistic significant differences,but the expression of PP2A C.increased with no statistic significant differences.Conclusion:Calcium-associated proteins in CAMR_TG mice showed abnormal expression,which leaded to arrhythmia and hypertension.The arrhythmia in transgenic mice was aggravated after exhaustive physical activity,which triggered the sudden death.Transgenic mice showed intracerebral hemorrhage because of abnormal vascular tone and amyloid deposit in brain vessels after exhaustive physical activity when the hormone level increased.